Seriously, I don't understand the discussion here. It's a solved problem, and the solution is what vimium does: press a key that opens a tab searcher and digit a bunch of characters related to the tab you want to go to, and you get presented with an ever-shrinking list of tabs (favicon, title, hostname, ..) that match your search as you type. Enter, maybe one or two arrows movements to select the final choice.
If you have 2 tabs or 2000 tabs it doesn't matter, going to a tab it's always a sub-second operation.
It is kinda native, at least in firefox: CTRL+L opens the address bar and on there you can search between open tabs. In my opinion it just needs some small UI improvements because at the moment the visual indicators to differentiate between open tab, search, history item, favorite in the results are not clear enough and the results are (or appear) mixed.